Pry-out for switch boxes and the like



Jan. 2, 1934- c. NEWMAN HAL Q 1,941,,99? I FRY-OUT FOR SWITCH soxzs AND THELIKE Filed Jan. 2, 1930 1 Charles w/wman.

, (ll/alter O Roaah.

dam. 2, 1934 PRY-OUT FOR SWITCH BOXES AND THE LIKE Charles Newman, New York, N. Y., and Walter 0.

, Roach, Chicago, 111., assignors, by mesne assignments, to Roach Appleton Manufacturing Company, South Bend, Ind., a corporation of Delaware Application January 2, 1930. Serial No. 418,052 11 Claims." (Cl. 247-26) The present invention relates to pry-outs for adapted to operate as a hinge. Each knock-outis defined by a disrupted part of the metal, the line switch boxes and the like.

More particularly the present invention relates to removable closure means suitable for switch boxes or receptacles as commonly provided in the protective means for electric circuits.

It has been common practice to provide receptacles of the kind referred to with partially severed closure means commonly known as knockouts. Comparatively recently, partially severed closure means have been provided which are adapted to be pried out from the receptacle or switch box, thereby avoiding the danger that a workman will injure his hands, which danger was always present in the old style of knock-out.

An object of the present invention is to provide a pry-out for a switch box or the like which is more readily removable than has been the case heretofore.

A further object is to provide a switch box having readily removable pry-outs which lie flush with the walls in which said pry-outs are located.

A further object is to provide a switch box having a wall provided with a pry-out, said wall and pry-out having the advantage that a maximum of leverage effect may be attained with a simple prying member with a minimum size of hole for the insertion of such prying member.

Further objects will appear as the description proceeds.

Referring to the drawing- Figure 1 is a view in side elevation of a switch box employing pry-outs embodying the principles of the present invention;

Figure 2 is a plan view looking toward the open side of the switch box shown in Figure 1;

Figure 3 is a sectional view taken along the plane indicated by the arrows 3-3 of Figure 2;

Figure 4 is a fragmentary view illustrating a modification of the type of pry-out illustrated in Figures 1, 2 and 3; and

Figure 5 illustrates a still further modification of pry-out.

The numeral indicates a switch box or other casing having side walls and a bottom wall. The particular switch box chosen for illustration is provided with box supporting ears 11-11, which, however, form no part of the present invention. Each of the side walls and the bottom wall of the switch box 10 is shown as being provided with pry-outs, said pry-outs being indicated by the numeral 12. In each instance the pry-out is shown as being defined by part of the circumference of circle, an 'intact portion 13 being provided of rupture being indicated by the numeral 14. The line of rupture may extend entirely through the wall in which it is located, or, if preferred, it may define merely a line of weakened material.

In the switch box illustrated, the pry-outs 12-12 are shown in pairs. Clamps 15-15 may be provided, each having a pair of clamping portions 16-16. vEach of said clamping portions is adapted to have clamping relationship with a cable 17 entering the switch box through the opening provided by a detached pry-out. The clamping portions 16-16 may have an arcuate contour, whereby to hug more or less closely the 7 periphery of the cable 1'7. Disposed in rightangular relationship with the arcuate shapes of the portions 16-16 is the wall 18 adapted to contact with an adjacent wall of the switch box 10. A screw 19, which may be threaded into a our,- 5 responding hole in one of the walls of the switch box 10, serves to hold the clamping member 15 in clamping relationship with either one ortwo cables 1'7. Figure 3 shows the clamp 15 in clamping relationship with one cable 1'7, the other ex-' 50 tremity of said clamping member '15 having an abutment against the bottom wall of the switch box 10. g

The walls of the switch box illustrated in Figures 1, 2 and 3 are provided withapertures 20-20, preferably elongated in contour, adapted to receive prying members. Said apertures 20-20 in the form illustrated in Figures 1, 2 and 3 are disposed both within the outline of the circumferential line 14 and in the material of the wall outside of said circumferential line 14. Expressed in other language, the prying openings 20-20 in the switch boxes shown in Figures 1,

-2 and 3 are disposed both within the circle defining the pry-out 12 and the wall of the switch 5 box outside of said circle. This construction has the advantage that a maximum of prying effect may be attained with a minimum of size of the opening 20. It will be understood that by the insertion of a prying member of the simplest kind, an elfective fulcrum will be provided by the edge of the opening disposed within the wall of the box, the leverage eirect of the prying mem-- her being applied to the edge of the opening lying within the contour of the pry-out.

In the form of the invention shown in Figure 4, an opening 21 is provided lying entirely within the circumference of the circle 14 defining the line of rupture of the pry-out 12. In the form shown in Figure 1, one side of the opening 21 is 7 defined by said circle 14. In the form of the invention shown in Figure 5, a prying opening 22 is provided, which lies entirely within the corresponding pry-out 12..

The slot-like openings 20, 21 and 22, it will be observed, are elongated in a direction at right angles to the diameter which includes the intact portion. This is the preferred direction of said openings, though this right-angular relationship is not essential in the performance of the functions of the device. Said openings will snugly receive the bit of a screwdriver, thereby permitting an efficient prying action with a tool which an artisan ordinarily has at hand, while presenting a minimum of area for the egress of flame or sparks from within the box.

The pryouts 12-12'may be left flush with the walls in which they are located. Such an arrangement is illustrated in the figures of the drawing. This structure has the advantage that the pry-outs add nothing to the overall dimensions of the switch box, whereby the switch box may be inserted into a hole of minimum dimensions.

Though certain preferred embodiments of the present invention have been described in detail, many modifications will occur to those skilled in the-art. It is intended to cover all such modiflea-tions that fall within the scope of the append ed claims.

What is claimed is:--

1. In electric protective means, a casing having a pry-out in a wall thereof, said wall, at the region of said pry-out, being provided with a slot-like opening for the reception of a prying tool whereby said pry-out may be pried loose from said wall, said pry-out being defined by a portion of the circumference of a circle, said opening being disposed partly within and partly without said circle.

2. In electric protective means, a casing having a pry-out in a wall thereof, said pry-out being substantially flush with said wall and being provided with a slot-like opening for the reception of a prying tool whereby said pry-out may be pried loose from said wall.

3. In electric protective means, a casing having a' pry-out in a wall thereof, said wall at the region of said pry-out being provided with a slot-like opening for the reception of a prying tool whereby said pry-out may be pried loose from said wall, said opening having one edge thereof defined by the material of the wall bounding said pry-out.

4. In electric protective means, a casing having a pry-out in a wall thereof, said pry-out being provided with an edge portion providing an abutment for a prying tool, said edge portion being defined by a slot-like opening extending through the thickness of said wall.

5. In electric protective means, a casing having a pry-out in a wall thereof, said pry-out being provided with an edge portion providing an abutment for a prying tool, said edge portion being defined by a slot-like opening extending through the thickness of said wall, said pry-out being substantially flush with said wall.

6. A casing having a wall portion provided with a pry-out, said pry-out being defined by a single line of rupture, which line of rupture is interrupted by a single intact portion, said pry-out being formed within the boundary of said line of rupture with a slot-like opening providing abutment means for the reception of a prying tool.

7. In an outlet box having a knock-out, said knock-out being defined by a perforation interrupted by a fin or intact portion, said knock-out also being provided with aslot-like opening therethrough through which the fiat bit of a tool such as a screw-driver may be inserted to move the knock-out about an axis in the plane of the knock-out and thereby remove the knock-out, the said opening being entirely bounded, in the plane of the knock-out, by the material of the knockout per se.

8. In an outlet box having a knock-out, said knock-out being defined by a perforation interrupted by a fin or intact portion, said knock-out also being provided with an opening therethrough through which a tool may be inserted for removing the knock-out, the said opening being entirely bounded, in the plane of the knock-out, by the material of the knock-out per se.

9. In electric protective means, a casing having a pry-out in a wall thereof, said pry-out being provided with an opening for the receptionof a prying tool whereby said pry-out may be pried loose from said wall, said pry-out being defined by a portion of the circumference of a circle, said opening being disposed partly within and partly without said circle, said opening being elongated and having its long dimension lying substantially in the circumference of said circle.

10. In an electric protective system, a casing having a wall portion provided with a pry-out, said pry-out being substantially flush with said wall portion and said pry-out being defined by a single lineof rupture which line of rupture is interrupted by a single intact portion, said pryout being provided with an opening for the reception of a prying tool whereby said pry-out may be pried loose from said wall portion, said pry-out being defined by a portion of the circumference of a circle, said opening being disposed partly within and partly without-said circle,'said opening being elongatedfand having its long dimension lying substantially in the circumference of said circle. 1

11. An outlet box having a pry-out in a wall thereof, said pry-out being defined by a perforation interrupted by a fin or intact portion, said wall being provided at the region of said pry-out with a slot-like opening therethrough through which the fiat bit of a tool such as a screw-driver may be inserted to remove the pry-out.

CHARLES NEWMAN. WALTER O. ROACH. 

